Range transmission


The tractor range transmission is located in the front portion of the tractor rear frame. The range tractor transmission is equipped with Hi (direct drive), Lo (under drive), neutral and reverse. 

On tractor models equipped with Forward-Reverse transmission, range transmission uses only Hi, Lo and neutral as reverse is provided by the Forward-Reverse unit. The light  duty band and drum type transmission park brake is located in the range tractor transmission. The heavy duty park brake is located on the differential ring gear. To remove the range transmission, tractor rear main frame (range section) must be separated from speed gearbox and the differential and the hydraulic lift housing removed.

OVERHAUL

With the engine and speed gearbox assembly separated from the range section, remove hydraulic lift housing. Remove the differential assembly.

Remove snap rings (2). Drive out roll pins (1) and rotate shift rail (3) to disengage detent balls (4) from slots in rail. Move shift rail forward and cover shift fork (6) with a shop towel to prevent losing detent ball and spring. Rotate shift fork to remove bushing (7), then remove Lo-Reverse shift fork. Remove Hi-Neutral shift fork (16) in same manner. Removal of shift levers and shift arms is obvious after examination of the units and reference to Figure.

On tractor models equipped with Forward-Reverse transmission, only one shift lever and shift fork is used.

Shift levers, shift rail and shift forks used on range transmission

1.Roll pins, 2.Snap rings, 3.Shift rail, 4.Detent balls, 5.Detent springs, 6.Lo-Reverse shift fork, 7.Bushings fork, 8.Nuts, 9.Shift arms, 10.Spacer plate, 11.Washers, 12. Needle bearings, 13.'0" rings, 14.Washers, 15.Lo-Reverse shift lever, 16.Hi-Neutral shift fork, 17,Washer, 18.Interlock plate, 19.Hi-Neutral shift lever

2 wheel drive tractors

To remove the bevel pinion mainshaft (1), loosen park brake adjustment, then unpin and remove park brake band (6). Remove snap ring (9) from groove in bevel pinion shaft. Unbolt bearing housing (3), move bevel pinion shaft rearward and remove Hi sliding collar (16), Remove Lo-Reverse gear (15), snap ring (9) and brake drum (8). Remove bevel pinion mainshaft assembly with shims (5) from transmission case. Measure and note thickness of shims if the same bevel pinion main shaft is to be reinstalled.  Using a dial indicator, measure end play of bearing housing (3) on bearings (2 and 4). If end play is more than 0.009 inch (0.229 mm), renew the bearings as follows: 
Remove snap ring (7) and press bearings and housing from bevel pinion main shaft. Install new bearings (2 and 4) and housing (3) and secure with snap ring (7).

To remove the countershaft (25), remove snap ring (18) and remove snap ring (24) from its groove in countershaft. Drive a wedge into split in spacer (22). Move countershaft forward and remove snap ring (24), Lo gear (23), split spacer (22) and constant mesh gear (21) as countershaft is withdrawn. Remove snap ring (17), then press ball bearing (19) from counter-shaft. Pump drive gear (29) is located on pto driven shaft and rides in needle bearing (27). If necessary, countershaft needle bearing (26) and pump gear needle bearing (27) can now be removed. Note position of needle bearings before removing.
To remove the reverse idler gear (35) and shaft (32), drive out roll pin (33). Withdraw shaft (32) and remove reverse idler gear (35) with needle bearings (34 and 37) and spacer (36), then remove thrust washers (31 and 38).

Clean and inspect all parts and renew any showing excessive wear or other damage. If bevel pinion mainshaft must be renewed, bevel ring gear must also be renewed as they are available only as a matched set.
To set bevel pinion mainshaft position, install bearings (2 and 4), housing (3) and snap ring (7). The mounting distance (A) from mainshaft pinion bearing housing mounting face to the center line of the differential is approximately 6.600 inches (167.64 mm). This distance may vary for each tractor. To aid in accurate installation of the pinion main-shaft, a single figure is stamped on the top face of the upper pto shaft boss. The single figure indicates (in inches) the variation from distance (A) in steps of 0.001 inch (0.025 mm). When distance (A) is smaller, a minus sign will be shown in front of single figure. Add or subtract the single figure to the approximate distance 6.600 inches (167.64 mm). The pinion cone mounting distance (B) is marked (in inches) on the rear face of the pinion and shows the distance this face must be from center line of differential. The distance will be approximately 4.410 inches (112.01 mm). 


Stand pinion shaft on a flat surface. Measure distance from pinion face to the bearing housing mounting face. This is distance (C). Add distance (C) to the marked figure on pinion face (distance B) and subtract from the resulting (distance A). The final figure is the correct thickness of shims (5) to be installed for correct pinion mainshaft position. The balance of reassembly is the reverse of disassembly procedures.

Range transmission without front drive axle. Note the light duty park brake (6 and 8)

1.Bevel pinion mainshaft , 2.Rear bearing,3.Bearing housing, 4.Front bearing, 5.Shim, 6.Brake band, 7.Snap ring, 8.Brake drum, 9.Snap ring, 15.Lo-Reverse gear, 16.Hi sliding collar, 17.Snap ring, 18.Snap ring, 19.Ball bearing, 20.Snap ring, 21.Constant mesh gear, 22.Split spacer, 23.Lo gear, 24.Snap ring, 25.Countershaft, 26.Countershaft needle bearing, 27.Pump drive gear needle bearing, 28.Snap ring, 29.Pump drive gear, 30.Snap ring, 31.Thrust washer, 32.Shaft, 33.Roll pin, 34.Needle bearing, 35.Reverse idler gear, 36.Spacer, 37.Needle bearing, 38.Thrust washer